Spring suspension device for cycles and motorcycles



y 1942' A. o. FINLAY ETAL I 2,283,671

SPRING SUSPENSION I DEVIGE FOR CYCLES AND MOTORCYCLES Filed Feb. 13, 1940 2 Sheets-Sheet 1 4zzez zzrwza g 2 05812 (SE w ZW Q- .May19,1942. I A, D, HNLAY Em 2,283,671"

SPRING SUSPENSION DEVICE FOR CYCLES AND MOTORCYCLES Filed Feb. 13, 1940 2 Sheets-Sheet 2 Patented May 1 9, 1942 i SPRING SUSPENSION DEVICE FOR CYCLES AND MOTORCYCLES Albert Daley Finlay and Robert stead Finlay,

Melbourne, Victoria, Australia Application February 13, 1940, Serial No.

In Australia March 16, 1939 3 Claims.

This invention relates to spring suspension devices for cyclesand motor cycles and its object is to provide an improved construction of this type which is light, strong and effective and is applicable to both the front and rear wheels of the machine.

Referring to the drawings which form part of this specification:

Figure 1 is a side elevation of the rear portion of a cycle frame showing the invention applied thereto, portions being broken away for convenience of illustration.

Figure 2 is a sectional plan on the line II-II of Figure 1.

Figure 2a is a side view showing a modified construction of the rear spring fork.

Figure 3 is an enlarged section on the line IIIIII of Figure llooking in the direction of the arrows.

Figure i is a side tion of a cycle frame plied thereto.

Figure 4a is a sectional plan on the line IVIV of Figure 4.

Figure 5 is a front view of Figure 4, parts being broken away.

Figure 5a. is an enlarged cross section of the elevation of the front por. showing the invention ap- 7 further modified forms ,nection between the Figure 12 is across sectional view on the line XIIIIHII of Figure 11.

Figures 13 to 19 inclusive are side views of of the said resilient conupper ends of the rear diagonal stays and the adjacent part of the cycle frame.

Figure 20 is an enlarged cross section on the line XX-XX of Figure 16.

According to the invention, the front fork 2 of the machine or portion thereof is constructed of spring material which may consist of flattened metal tubing or, if desired, of plate spring material, the tubular members of the fork 2 on either side of the wheel being preferably tapered or of gradually decreasing thickness and curved downwardl and forwardly towards their lower ends as indicated at 2 inFi'gures 4 to '7 inelusive.

'The lower ends of the said front spring fork I members are adapted to receive the front wheel flattened metal tubing forming the spring portion of the front fork members.

Figure 6 is an enlarged detail view showing in part sectional side elevation the resilient mounting of the front axle of the cycle in the lower end of an outrigger hereinafter described.

Figure 7 is a part sectional front view of Figure 6 showing the abovementioned resilient mounting of one end of the front axle in one of the outrigger legs.

Figure 8 is an enlarged fragmentary view in side elevation of a modified form of resilient connection between the upper end of the front fork and the upper end of the aforesaid outrigger which is located in front of said fork, parts being broken away for convenience of illustration.

Figure 9 is a part sectional front view of Figure 8.

Figure 10 is a fragmentary side elevation of a modified type of resilient connection between the upper ends of the rear diagonal stays and the rear part of the cycle frame adjacent the saddle pillar.

Figure 11 is a similar view of a further modified type of resilient connection between the upper ends of the rear diagonal stays and the adjacent part of the cycle frame.

axle 3 and around this axle, at either side of the wheel 5, is a resilient sleeve 4 of rubber or the like which is interposed between inner and outer metal sleeves 6a.

Clamped aroundthe said sleeves at either side of the front wheel are the lower ends'of the two legs 6 of an outrigger which may be composed of light and strong metal bars and is adapted to prevent sideward movements of the wheel and control or stabilise the action of the spring fork. The sleeves 4 form resilient bearings between the lower ends of the outrigger legs 6 and the front axle 3.

The legs of the outrigger 6- extend upwardly above the front wheel and their upper ends, which are disposed in front of the steering neck 1 of the cycle frame, are provided with holes to receive a pivot pin 8 to which is connected a disc or the like 9 which engages the lower end of a coiled spring II. The upper end of this spring engages a similar disc or the like I2 on a yoke l3 hereinafter described. A rubber buffer l5 may extend from the disc l2 through the spring II to retain the latter in position and absorb any rebound. g r

' Also formed on the legs of the outrigger 6 near the upper ends thereof are lugs l4 (Figs. 4 and 4a) to accommodate a rear pivot pin I 6 which passes'through a transverse sleeve on the rear end of a shackle link may comprise a pair of laterally spaced arms (Fig. 5) the forward ends of which carry a front pivot pin l9 which is disposed in front of the outrigger 6.

I! (Fig. 4a) Hi. This link Pivoted to the said front pivot pin 13 is the intermediate portion of the aforesaid yoke [3, the lower portion of which extends downwardly and rearwardlyas in Figure 4 and the lower end of which is attached to a lug 2| on the upper end of the front spring fork 2 with which the yoke and the outrigger may swivel bodily in accordance with the steering movements of the front wheel 5.

The upper end of the yoke I3 is pivoted to the swivelling steering column 22 above the steering neck 1 of the main frame and the aforesaid coiled spring II is disposed between and the steering neck I and presses at its upper and lower ends against the aforesaid discs or the like 9 and I2 on the yoke 13' and on the upper end of the outrigger 6 respectively.

The rear wheel 23 of the machine is preferably mounted between the laterally spaced members of a substantially horizontal rear spring fork 24 (Figs. 1 and 2) which may also be constructed of metal tubing flattened as at 24 to form spring forks extending rearwardly to the bearing members or brackets 26 which accommodate the axle of the rear wheel '23.

Instead of forming the rear spring forks of flattened metal tubing as aforesaid, plate spring strips 24 may be secured by brazing or other means to the bearing members 26 and the front portions of the rear fork 24 as in Figure 2a.

Extending upwardly and forwardly from the bearing members 26 on the rear spring fork 24 are diagonal rear stays 21, theupper ends of which are pivoted to the rear end of a rear shackle link 28, which may also comprise a pair of laterally spaced arms similar to the front shackle link 18 previously referred to. This rear link 28 is pivoted at its forward end to a suitable adjacent part of the cycle frame, such, for instance, as the top horizontal member 29 of the main frame which extends forwardly from the saddle bracket 31 to the steering neck 1 within which turns the steering column 22. V

A cross piece 32 is provided on the upper portion of the said diagonal rear stays 21 and attached to this cross piece and to a lug 30 on the rear member 33 of the main frame which extends downwardly and forwardly from the saddle bracket 3| to the pedal shaft bracket 34, are discs or the like 36 and 31 between which a coiled spring 38 is arranged and adapted to absorb shocks transmitted from the rear wheel through the diagonal rear stays 21.

By means of the foregoing construction a light, strong and efficient means of suspension of the cycle or motor cycle frame on the front and rear wheels is provided, so that road shocks and vibrations are reduced to a minimum and riding comfort is greatly enhanced.

According to a modificatiomthe resilient connection between the upper ends of the outrigger legs 6 and the upper end of the front fork 2 may be constructed as illustrated in Figures 8 and 9. In this modification the upper end of the front spring fork 2 is provided immediately beneath the steering neck 1 with a forwardly extending lug 33 carrying a transversely disposed tubular sleeve 31. Accommodated by this sleeve is a cylindrical rubber buffer 40 through which passes the yoke I 3 a transverse pin or bolt 39 which is attached to the upper ends of the outrigger legs 6. Side cheeks 41 are fitted around the pin 39 between the ends of the rubber buffer 40 and the flattened upper ends of theoutrigger legs 6 as seen in Figure 9.

The resilient connection between the upper horizontal member 29 of the cycle frame.

ends of the rear diagonal stays 21 and the adjacent part of the cycle frame as illustrated in Figures 1 and 3 may also be modified in various ways as illustrated in Figures 10 to 20 inclusive.

According to the modification illustrated in Figure 10 the upper ends of the diagonal rear stays 21 may be pivoted as at 42 to the rear end of a link 43, the front end of which is pivoted as at 44 to a downward extension 45 of the aforesaid In this embodiment endless elastic straps 46 may pass around a transverse pin or roller 41. on the link 43 and around a co-operating pin or roller 48 on an adjusting screw or bolt 49 which passes through an internally threaded block 5| on a lug 52 carried by the aforesaid member 33 of the cycle frame.

According to the modification illustrated in Figures 11 and 12, the upper ends of the diagonal rear stays 21 are connected to a transverse pivot pin 53 attached to a socket 54 which slidably accommodates a diagonally disposed stem 56 extending downwardly and rearwardly from the frame member 33. The pivot pin, 53 passes through elongated slots 51 in the stem 55which is prevented from turning within the socket 54 by means of a key or feather 58. Sliding movement of the socket 54 in relation to the stem 56 may be suitably checked by means of a fibre or like pad or damper59 (Figure 12) which may be accommodated in a branch 6| of the sleeve 54 and is pressed against'the stem 56 by a spring 62, the pressure of which may be adjusted by a screw threaded cap 63. Interposed between the sleeve 54 and a shoulder 56a on the stem 56 is the coiled spring 38 .which corresponds to the spring shownin Figures 1 and 3. A stop 56b is provided on the lower end of the stem 56' to limit its sliding movement within the sleeve 54.

A similar modified arrangement is shown in Figure 13 where the sleeve 54 slidably accommodates a pair of rearwardly and downwardly extending diagonal stems 56 on the frame member 33, the spring 38 encircling the stems 56 between the sleeve 54 and the shoulder 56a on'said stems which'are provided at their lower ends with the limit stops 55b.

According to themodification illustrated in Figure 14 the spring 33 is accommodated inatele scopic casing one section64 of which is attached to the upper ends of the diaginal rear stays 21 while the other section 65 of the telescopic casing is pivoted as at B'l'to a lug on the frame member 33.. In the modification illustrated in Figure 15 a rubber or like buffer or cushion 68 is accommodated between cupped members or discs 69, H, the former of which is attached to the upper ends of the diagonal rear stays 21 whilst the latter is pivoted as at T2 to a lug on the frame member 33.

Figures ldand 20 show a further modified'arrangement accordingto which the upper ends of the rear stays 21 are pivoted to a transverse pin 13 passing through slide blocks 14 which are adapted to slide within guideways formed in a diagonal rib 16 extending between the frame member's29 and 33. This diagonal rib is provided with a slot l'l 'to slidably accommodate the pivot pin 13. In this case the spring 38..is accommodated between discs or the like 36 and 31 which are carried .respectively bythe aforesaid vcrojss piece 32 ,on the diagonal rear stays 21 and by the lug Silpn .the frame. membe,r 33

bell crank lever or link!!! which is intermediately pivoted as at 8! to a lug on the frame member 33, spring check nuts 82 being preferably fitted on the ends of the pivot pin 8|. The other arm of the bell crank lever or link 19 is connected to -a pivot pin 83 which passes through elongated slots 84 in the tubular frame member 33 and is connected to a rod 86 which is slidably accommodated within the frame member 33. This rod is encircled by the spring 38 which in this case is also accommodated in the tubular frame member 33 and is compressed by the sliding movement of the rod 86 in accordance with the movements of the stays 21 and the bell crank lever 19.

A somewhat similar arrangement is shown in Figure 18 where the bell crank lever or link 19 is attached to a disc or the like 88 between which, and the frame member 33, the spring 38 is suitably retained.

According to the further modification illustrated in Figure 19, the bell crank lever or link 79, which is pivotally mounted on the frame member 33 and pivotally connected at one end to the upper ends of the diagonal rear stays 21 as aforesaid, is pivoted at its opposite end as indicated at 89 to a rod 9| which passes slidably through the frame member 33 and is encircled by the spring 38 which is compressed between the frame member 33 and a disc or the like 92 and the rod 9!.

It will be evident that the modified construction illustrated in Figures 8 and 9 may be substituted for the resilient connection between the upper end of the outrigger 6 and the upper end of the front fork 2 whilst either of the modifications illustrated in Figures 10 to 20 inclusive may be substituted for the resilient connection between the upper ends of the diagonal rear stays 21 and the adjacent part of the cycle frame as described with reference to Figures land 3.'

We claim: 1 1. A spring suspension for cycles, including a main frame including an upright member, a pair of fork members connected to said upright member and extending rearwardly therefrom to accommodate a wheel between them, each fork member being of tubular stock, flattened and diametrically increased for a portion of its length to provide a section of relatively increased resiliency, the ends of the resilient sections being terminally formed to support a wheel axle, a stay extending upwardly and forwardly from the axle-receiving end of each fork member, the upper ends of the stays extending forwardly of and on opposite sides of the upright member of the main frame, and a shackle supported by a member of the main frame and towhich the upper ends of the stays are connected forward of the upright member of the main frame.

2. A construction as defined in claim 1 wherein a spring cushion is interposed between the stays and the upright member of the main frame rearwardly of said upright member.

3. A construction as defined in claim 1, wherein the stays are provided rearwardly of the upright member of the main frame with a rigid connecting element, and wherein the upright member of the main frame is also provided with a similar element, with said elements in line in the plane of the stays, together with a spring between and bearing against said elements.

ALBERT DALEY FINLAY. ROBERT STUDDY FINLAY. 

